Meaning of Nansen bottle

Nan'sen bot"tle

Pronunciation: [key]
— Oceanog. Oceanog.
  1. a waterproof container for taking samples of ocean water, several usually being lowered open on a line and each being closed at the desired depth by the action of a falling weight.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.